Special Issue

Keiichiro Fukumoto's Special Issues, Vol. 77, No. 2, 2009

69 data found. 31 - 60 listedFirst Previous Next Last
Paper | Special issue | Vol 77, No. 2, 2009, pp. 953 - 970
Published online: 22nd September, 2008
DOI: 10.3987/COM-08-S(F)70
Pterdines CXX. Synthesis and Properties of Tetrahydropterins Coupled to 1,4-Dihydropyridines

Joachim Rehse and Wolfgang Pfleiderer*

*Department of Chemistry, University of Konstanz, Posttach 55 60, 78434 Konstantz, Germany

Abstract

N2-Isobutyroyl-5,6,7,8-tetrahydropterins (6-10) have been coupled with nicotinic acid to form the N5-nicotinoyl derivatives 11-15. Quaternization at the pyridine moiety led to 19-31 which can be reduced to the corresponding N-substituted 1,4-dihydropyridine dertivatives 35-39. Partial deacylation of the isobutyroyl group afforded the various types of terahydropterins 16-18, 32-34 and 40-42. The newly synthesized 5,6,7,8-tetrahydropterin derivatives have been characterized by pKa-determinations, UV- and NMR-spectra as well as elemental analyses.

Full Text HTMLPDF (761KB)PDF with Links (903KB)
Paper | Special issue | Vol 77, No. 2, 2009, pp. 971 - 982
Published online: 2nd October, 2008
DOI: 10.3987/COM-08-S(F)71
Nucleophilic Substitution Reaction in Indole Chemistry: 1-Methoxy-6-nitroindole-3-carbaldehyde as a Versatile Building Block for 2,3,6-Trisubstituted Indoles

Koji Yamada, Fumio Yamada, Takei Shiraishi, Saori Tomioka, and Masanori Somei*

*Faculty of Pharmaceutical Sciences, Graduate School of Natural Science and Technology, Kanazawa University, Kakuma, Kanazawa, Ishikawa 920-1192, Japan

Abstract

1-Methoxy-6-nitroindole-3-carbaldehyde is proved to be a versatile electrophile and reacts regioselectively at the 2-position with various types of nucleophiles providing 2,3,6-trisubstituted indole derivatives. The reaction is applicable for the preparation of a novel pyrimido[1,2-a]indole derivative.

Full Text HTMLPDF (275KB)PDF with Links (1.1MB)
Paper | Special issue | Vol 77, No. 2, 2009, pp. 983 - 990
Published online: 11th September, 2008
DOI: 10.3987/COM-08-S(F)72
A Convenient Synthetic Method for Fluorine-containing 4-Alkoxy-dihydrobenzo[b][1,4]diazepinols and 3H-Benzo[b][1,4]diazepines by the Reaction of β-Trifluoroacetylketene Acetals with 1,2-Phenylenediamines

Norio Ota, Etsuji Okada,* Naoya Terai, Tomomi Miyamura, Dai Shibata, and Tsuneaki Sakai

*Department of Chemical Science and Engineering, Faculty of Engineering, Kobe University, Rokkodai-cho, Nada-ku, Kobe 657-8501, Japan

Abstract

β-Trifluoroacetylketene dialkyl acetals (3 and 5) reacted easily with various 1,2-phenylenediamines to give novel 4-alkoxy-2-trifluoromethyl-2,3- dihydro-1H-benzo[b][1,4]diazepinols (6 and 8) in moderate to high yields. Dehydration of 6 and 8 proceeded thermally under reduced pressure to afford the corresponding fluorine-containing 3H-benzo[b][1,4]diazepines (7 and 9).

Full Text HTMLPDF (207KB)PDF with Links (899KB)
Paper | Special issue | Vol 77, No. 2, 2009, pp. 991 - 1005
Published online: 29th September, 2008
DOI: 10.3987/COM-08-S(F)85
Selective Lithiation of 4- and 5-Halophthalans

Daniel García, Francisco Foubelo,* and Miguel Yus*

*Department of Organic Chemistry, Faculty of Sciences and Institute of Organic Synthesis (ISO), University of Alicante, P.O. Box 99, 03080 Alicante, Spain

Abstract

The reaction of 4- and 5-halophthalans 5 with lithium and a catalytic amount of DTBB at -78 °C leads to the formation of the corresponding functionalized organolithium intermediates 6 and 11, which by reaction with carbonyl compounds give, after hydrolysis, the expected substituted phthalans 8 and 13, respectively. When after reaction with the carbonyl compound the system is allowed to react at 0 °C, a second lithiation occur: A reductive opening of the heterocycle takes place with some regioselectivity leading to new organolithium intermediates 9 and 14/15 that by reaction with electrophiles lead, after hydrolysis, to polyfunctionalized molecules 10 and 16/17, respectively.

Full Text HTMLPDF (326KB)PDF with Links (977KB)
Paper | Special issue | Vol 77, No. 2, 2009, pp. 1007 - 1018
Published online: 6th October, 2008
DOI: 10.3987/COM-08-S(F)78
Heterogeneous Lewis Acid Catalysis with Self-organized Polymeric Rare Earth Arylsulfonates under Solvent-free Conditions

Hiroshi Furuno,* Shuichi Ishida, Shoko Suzuki, Tetsuji Hayano, Satoaki Onitsuka, and Junji Inanaga*

*Synthetic Methodology and Catalysis, Institute for Materials Chemistry and Engineering (IMCE), Kyushu University

Abstract

Polymeric rare earth arylsulfonates, easily prepared from rare earth triisopropoxides and biphenyl-4,4’-disulfonic acid (BPDSA) or 1,3,5-triphenylbenzene trisulfonic acid (TPTSA) in a self-organization manner, were found to work as an efficient heterogeneous Lewis acid catalyst for the hetero-Diels-Alder reaction of aldehydes with the Danishefsky‘s diene and the ring-opening reaction of epoxides with amines under solvent-free conditions. The catalysts could be quantitatively recovered and reused many times without decreasing their activities.

Full Text HTMLPDF (1.2MB)PDF with Links (1.1MB)
Paper | Special issue | Vol 77, No. 2, 2009, pp. 1019 - 1035
Published online: 2nd October, 2008
DOI: 10.3987/COM-08-S(F)80
Synthesis and Properties of Novel Biologically Interesting Polycyclic 1,3,4-Oxadiazoles Containing Acridine/Acridone Moieties

Zdenka Fröhlichová, Jana Tomascikova, Ján Imrich,* Pavol Kristian, Ivan Danihel, Stanislav Böhm, Danica Sabolová, Mária Kozurková, and Karel D. Klika

*Department of Organic Chemistry, P. J. Safárik University, Moyzesova 11, SK-041 67 Kosice, The Slovak Republic

Abstract

A series of polycyclic 1,3,4-oxadiazoles bearing acridine and acridone pharmacophores were synthesized as potential noncovalent DNA-binding and antitumor agents. The synthesis of oxadiazoles with acridone moiety was performed exploring oxidative cyclization of corresponding aldimines via bromine and the acridine derivatives by cyclization of acylthiosemicarbazides with mercuric oxide. The spectroscopic properties of the compounds in the case of acridonoxadiazoles showed an efficient binding activity to DNA (K = 5.3-9.2 x 104 M-1), whereas the acridine analogues are suitable as biomarkers. The structure of compounds were characterized by spectral methods (UV-vis, IR, 1H, 13C, and 2D NMR) and quantum-chemical calculations (DFT, ZINDO).

Full Text HTMLPDF (445KB)PDF with Links (1.1MB)
Paper | Special issue | Vol 77, No. 2, 2009, pp. 1037 - 1044
Published online: 29th September, 2008
DOI: 10.3987/COM-08-S(F)81
Ether Formation in the Hydrogenolysis of Hydroxymethylfurfural over Palladium Catalysts in Alcoholic Solution

Gerard C. A. Luijkx, Nina P. M. Huck, Gred van Rantwijk, Leendert Maat,* and Herman van Bekkum*

*Faculty of Chemical Engineering, Delft University of Technology, Julianalaan 136, 2628 BL Delft, The Netherlands

Abstract

5-Hydroxymethylfurfural, a product from renewable feedstock, was subjected to hydrogenolysis over palladium catalysts in 1-propanol aiming at the synthesis of 2,5-dimethylfuran, a potential transportation fuel enhancer. Intermediates are 5-hydroxymethyl-2-(propyloxymethyl)furan, formed with high selectivity, and 5-methyl-2-(propyloxymethyl)furan. Acetals are assumed to be initially formed. Acetalisation and hydrogenolysis are catalysed by traces of a Brønsted acid. Important variables are the palladium support and the solvent. In 2-propanol also ether formation takes place. In 1,4-dioxane mainly 2,5-bis(hydroxymethyl)furan is formed, in water ring opening becomes a major reaction. The formation of some side-products is discussed.

Full Text HTMLPDF (282KB)PDF with Links (682KB)
Paper | Special issue | Vol 77, No. 2, 2009, pp. 1045 - 1056
Published online: 16th October, 2008
DOI: 10.3987/COM-08-S(F)83
Efficient Synthesis of [2]Rotaxanes Based on Sequential Acetylene-Dicobalt Hexacarbonyl Complexation and Stopper Modification

Yuji Tokunaga,* Norihiro Ohiwa, Go Ohta, Yuji Yamauchi, Tatsuhiro Goda, Nobuhiko Kawai, Takumichi Sugihara, Youji Shimomura, and Tomonori Hoshi

*Department of Materials Science and Engineering, Faculty of Engineering, Fukui University, Bunkyo, Fukui 910-8507, Japan

Abstract

This paper describes an efficient end-capping method for the preparation of [2]rotaxanes, using acetylene–dicobalt hexacarbonyl complexation and subsequent transformation of the complexes into a series of vinylsilanes though hydrosilylation.

Full Text HTMLPDF (265KB)PDF with Links (914KB)
Paper | Special issue | Vol 77, No. 2, 2009, pp. 1057 - 1064
Published online: 27th October, 2008
DOI: 10.3987/COM-08-S(F)84
Preparation of 1,4-Bis[2-{2-(1-methyl-1H-imidazol-5-yl)ethynyl}-3-thienyl]benzene and Related Compounds

Kozo Toyota,* Kazuyuki Okada, Hiroshi Katsuta, Yasutomo Tsuji, and Noboru Morita

*Department of Chemistry, Graduate School of Science, Tohoku University, Aoba-ku, Sendai 980-8578, Japan

Abstract

1,4-Bis[2-{2-(1-methyl-1H-imidazol-5-yl)ethynyl}-3-thienyl]benzene, 1,4-bis[2-(2-ferrocenylethynyl)-3-thienyl]benzene, and some related compounds were prepared and their UV-visible spectra were studied.

Full Text HTMLPDF (298KB)PDF with Links (917KB)
Paper | Special issue | Vol 77, No. 2, 2009, pp. 1065 - 1078
Published online: 9th October, 2008
DOI: 10.3987/COM-08-S(F)86
A New Chiral Synthesis of Wieland-Miescher Ketone Catalyzed by a Combination of (S)-N-Benzyl-N-(2-pyrrolidinylmethyl)amine Derivative and Brønsted Acid

Yuichi Akahane, Kohei Inomata,* and Yasuyuki Endo

*Tohoku Pharmaceutical University, 4-4-1 Komatsushima, Aoba-ku, Sendai 981-8558, Japan

Abstract

New or known N-benzyl-N-(2-pyrrolidinylmethyl)amine derivatives bearing a variety of substituents on the aromatic ring were easily prepared from N-Boc-proline or N-Boc-prolinol. The enantioselectivity of the intramolecular asymmetric aldol reaction mediated by a combination of the amine derivative and Brønsted acid to prepare Wieland-Miescher ketone was examined in detail. During the examination, remarkable substitutional effects on the aromatic ring were observed. Development of a catalytic version of the reaction was successfully achieved by the use of N-[(9-anthracenyl)methyl]-N-(2-pyrrolidinylmethyl)amine in the presence of dichloroacetic acid.

Full Text HTMLPDF (250KB)PDF with Links (892KB)
Paper | Special issue | Vol 77, No. 2, 2009, pp. 1079 - 1088
Published online: 2nd October, 2008
DOI: 10.3987/COM-08-S(F)87
Preparation of Azulene Substituted Pyrazine and Quinoxaline Derivatives

Nozomi Furuta, Takuo Mizutani, Akira Ohta, and Kunihide Fujimori*

*Department of Chemistry, Faculty of Science, Shinshu University, Asahi, Matsumoto 390-8621, Japan

Abstract

2,3-Di(2-azulenyl)pyrazines and -quinoxalines were obtained by the reaction of di(2-azulenyl)ethanedione with diamines. Cyclodehydrogenation reaction of the pyrazine and quinoxaline derivatives with manganese dioxide afforded the corresponding azulene-fused quinoxaline and phenazine derivatives, respectively.

Full Text HTMLPDF (456KB)PDF with Links (975KB)
Paper | Special issue | Vol 77, No. 2, 2009, pp. 1089 - 1103
Published online: 29th September, 2008
DOI: 10.3987/COM-08-S(F)88
Mild and Efficient Deprotection of Acetal-Type Protecting Groups of Hydroxyl Functions by Triethylsilyl Triflate—2,4,6-Collidine Combination

Hiromichi Fujioaka,* Ozora Kubo, Kazuhisa Okamoto, Kento Senami, Takashi Okitsu, Takkuya Ohnaka, Yoshinari Sawama, and Yasuyuki Kita*

*Graduate School of Pharmaceutical Science, Osaka University, 1-6 Yamadaoka, Suita, Osaka 560-0871, Japan

Abstract

Deprotection of acetal-type protecting groups of hydroxyl functions has been studied in detail. The treatment of alcohol derivatives protected by acetal-type protecting groups with TESOTf—2,4,6-collidine followed by H2O-treatment produces the corresponding hydroxyl compounds in good yields. The characteristic features of the method are very mild and chemoselective, and acid-labile functional groups can tolerate these conditions.

Full Text HTMLPDF (321KB)PDF with Links (950KB)
Paper | Special issue | Vol 77, No. 2, 2009, pp. 1105 - 1122
Published online: 6th October, 2008
DOI: 10.3987/COM-08-S(F)89
A General Method for the Synthesis of N-Unsubstituted 3,4-Diarylpyrrole-2,5-dicarboxylates

Tsutomu Fukuda, Yukie Hayashida, and Masatomo Iwao*

*Department of Applied Chemistry, Faculty of Engineering, Nagasaki University, 1-14, Bunkyo-machi, Nagasaki 852-8521, Japan

Abstract

A general method for the synthesis of N-unsubstituted 3,4-diarylpyrrole-2,5-dicarboxylates (3) has been developed. The key reactions involved are the Hinsberg-type synthesis of dimethyl N-benzyl-3,4-dihydroxypyrrole-2,5-dicarboxylate (6) followed by palladium-catalyzed Suzuki-Miyaura coupling of its bis-triflate derivative (7). The N-benzyl protecting group of the resulting 3,4-diarylpyrrole-2,5-dicarboxylates (8) is cleanly removed under hydrogenolytic or solvolytic conditions.

Full Text HTMLPDF (671KB)PDF with Links (1MB)
Paper | Special issue | Vol 77, No. 2, 2009, pp. 1123 - 1146
Published online: 9th October, 2008
DOI: 10.3987/COM-08-S(F)91
Synthesis of Annulated 1,4-Dioxanes and Perhydro-1,4-oxazines by Domino-Wacker-Carbonylation and Domino-Wacker-Mizoroki-Heck Reactions

Lutz F. Tietze,* Arne Heins, Mohammad Soleiman-Beigi, and Christian Raith

*Institute of Organic and Biomolecular Chemistry, Georg-August-University, Tammannstr. 2, D-37077 Göttingen, Germany

Abstract

Palladium(II)-catalyzed domino reactions for the formation of 1,4-dioxanes and perhydro-1,4-oxazines starting from hydroxy alkenes are described. The domino-Wacker-carbonylation comprises a Wacker oxidation, subsequent CO-insertion and a nucleophilic substitution of the intermediately formed Pd-species. The domino-Wacker-Mizoroki-Heck reaction proceeds via a Wacker oxidation, subsequent insertion into the olefinic π-bond of α,β-unsaturated carbonyl compounds and β-hydride elimination.

Full Text HTMLPDF (345KB)PDF with Links (1.1MB)
Paper | Special issue | Vol 77, No. 2, 2009, pp. 1147 - 1161
Published online: 22nd September, 2008
DOI: 10.3987/COM-08-S(F)94
Benzimidazoline-Dimethoxypyrene. An Effective Promoter System for Photoinduced Electron Transfer Promoted Reductive Transformations of Organic Compounds

Eietsu Hasegawa,* Harumi Hirose, Kosuke Sasaki, Shinya Takizawa, Takayuki Seida, and Naoki Chiba

*Department of Chemistry, Faculty of Sciences, Niigata University, Ikarasi 2-8050, Niigata 950-2181, Japan

Abstract

2-(p-Methoxyphenyl)-1,3-dimethylbenzimidazoline (ADMBI) and 2-(o-hydroxyphenyl)-1,3-dimethylbenzimidazoline (HPDMBI) are used as reducing reagents in 1,8-dimethoxypyrene (1,8-DMP) sensitized, photoinduced electron transfer (PET) reactions. This system was effectively used for PET induced, reductive transformations of various organic substrates, including α,β-epoxy ketones, the olefin tethered 2-bromomethyl-1-tetralone, and o-allyloxy-iodobenzene, as well as for the deprotection reactions of dodecyl-2-benzoylbenzoate and N-sulfonylindole. The results of studies show that 1,8-DMP is a more effective sensitizer than the previously used 9-methylcarbazole for deprotection of N-methyl-4-picolinium ester.

Full Text HTMLPDF (695KB)PDF with Links (976KB)
Paper | Special issue | Vol 77, No. 2, 2009, pp. 1163 - 1170
Published online: 22nd September, 2008
DOI: 10.3987/COM-08-S(F)95
Dehalogenation and Barbier-Type Hydroxyalkylation of π-Deficient Haloheterocycles Using Indium

Eri Fukuda, Yukiko Takahashi, Natsumi Hirasawa, Osamu Sugimoto,* and Ken-ichi Tanji

*Laboratory of Organic Chemistry, School of Food and Nutritional Sciences, University of Shizuoka, 52-1 Yada, Shizuoka 422-8526, Japan

Abstract

The reaction of π-deficient haloheterocycles with indium metal in water gave corresponding dehalogenated heterocycles. The use of diluted hydrochloric acid instead of water accelerated the reductive reactivity of indium metal. Furthermore, Barbier-type additions proceeded by reactions of α-iodoheterocycles with indium in the presence of pivalaldehyde.

Full Text HTMLPDF (337KB)PDF with Links (784KB)
Paper | Special issue | Vol 77, No. 2, 2009, pp. 1171 - 1183
Published online: 18th September, 2008
DOI: 10.3987/COM-08-S(F)96
Synthesis and Structures of Alkynylchlorocyclotriphosphazenes and Their Cluster-forming Reactions with Octacarbonyldicobalt

Takashi Komuro, Kenichi Mori, and Hiromi Tobita*

*Department of Chemistry, Graduate School of Science, Tohoku University, Aoba-ku, Sendai 980-8578, Japan

Abstract

Cyclotriphosphazenes having p-tolylethynyl and chloro substituents N3P3{C≡C(p-Tol)}nCl6-n (1a: n = 2, 1b: n = 4; p-Tol = p-tolyl) were synthesized by the reaction of hexachlorocyclotriphosphazene (NPCl2)3 with 2 equiv of LiC≡C(p-Tol) in THF. 1a and 1b were characterized by spectroscopic methods and elemental analyses. The reactions of 1a and 1b with octacarbonyldicobalt Co2(CO)8 produced cobalt clusters containing tetrahedral C2Co2(CO)6(p-Tol) cluster units; namely, tetranuclear cluster N3P3{C2Co2(CO)6(p-Tol)}2Cl4 (2) and hexanuclear cluster N3P3{C2Co2(CO)6(p-Tol)}3{C≡C(p-Tol)}Cl2 (3). Crystal structures of 1a and 2 were determined by X-ray crystallography.

Full Text HTMLPDF (295KB)PDF with Links (863KB)
Paper | Special issue | Vol 77, No. 2, 2009, pp. 1185 - 1208
Published online: 29th September, 2008
DOI: 10.3987/COM-08-S(F)97
Synthesis of Marine Oxylipin Agardhilactone and its Analogues: A Structural Revision

Hiromi Miyaoka,* Yoshinori Hara, Ikuo Shinohara, Takao Kurokawa, Etsuko Kawashima, and Yasuji Yamada

*School of Pharmacy, Tokyo University of Pharmacy and Life Science, 1432-1 Horinouchi, Hachioji, Tokyo 192-0392, Japan

Abstract

Synthesis of four analogues of the marine oxylipin agardhilactone was carried out. The relative configuration of agardhilactone was determined by comparison with agardhilactone acetate and four analogues. Furthermore, synthesis of agardhilactone was achieved. The absolute configuration of agardhilactone was successfully determined by this synthesis.

Full Text HTMLPDF (381KB)PDF with Links (819KB)
Paper | Special issue | Vol 77, No. 2, 2009, pp. 1209 - 1217
Published online: 6th October, 2008
DOI: 10.3987/COM-08-S(F)99
Synthesis and Properties of 2’-Deoxy-trans-3’,4’-BNA with S-Type Sugar Puckering

Tetsuya Kodama, Kensaku Sugaya, Yasuki Harada, Yasunori Mitsuoka, Takeshi Imanishi, and Satoshi Obika*

*Graduate School of Pharmaceutical Science, Osaka University, 1-6 Yamadaoka, Suita, Osaka 560-0871, Japan

Abstract

2’-Deoxy-trans-3’,4’-BNA monomer, which was previous synthesized as part of a study on bridged nucleic acids with S-type sugar puckering, was introduced into an oligodeoxynucleotide using phosphoramidite chemistry, and the hybridization ability of the 2’-deoxy-trans-3’,4’-BNA-modified oligonucleotide with complementary DNA and RNA strands was evaluated. The 2’-deoxy-trans-3’,4’-BNA-modified oligonucleotide showed greatly improved hybridization ability compared to its 2’-methoxy congener (2’-methoxy-trans-3’,4’-BNA), which suggested that the sugar-restriction of nucleic acids to S-type conformation with appropriate design may be useful for development of DNA mimics.

Full Text HTMLPDF (604KB)PDF with Links (1.1MB)
Paper | Special issue | Vol 77, No. 2, 2009, pp. 1219 - 1234
Published online: 25th September, 2008
DOI: 10.3987/COM-08-S(F)103
Total Synthesis of (±)-Morphine

Kenji Uchida, Satoshi Yokoshima, Toshiyuki Kan, and Tohru Fukuyama*

*Laboratory of Synthetic Organic & Medicinal Chemistry, Schol of Pharmaceutical Sciences, University of Shizuoka, 52-1 Yada, Shizuoka 422-8526, Japan

Abstract

The morphinan skeleton was effectively synthesized by an intramolecular Mannich-type reaction. Further transformation led to the total synthesis of morphine.

Full Text HTMLPDF (682KB)PDF with Links (958KB)
Paper | Special issue | Vol 77, No. 2, 2009, pp. 1235 - 1248
Published online: 2nd October, 2008
DOI: 10.3987/COM-08-S(F)105
Synthesis of Mono-, Di- and Tribenzoporphyrins from their Soluble Precursors

Tetsuo Okujima,* Yusuke Hashimoto, Guangnan Jin, Hiroko Yamada, and Noboru Ono

*Department of Chemistry and Biology, Graduate School or Science and Engineering, Ehime University, Matsuyama 790-8577, Japan

Abstract

Soluble precursors of β-, meso-unsubstituted mono-, di- and tribenzoporphyrins were prepared by the reaction of dimethylbicyclo[2.2.2]octadiene-fused pyrrole with appropriate β-free pyrroles. The retro Diels-Alder reaction of these precursors afforded the corresponding benzoporphyrins in quantitative yields.

Full Text HTMLPDF (261KB)PDF with Links (995KB)
Paper | Special issue | Vol 77, No. 2, 2009, pp. 1249 - 1259
Published online: 31st October, 2008
DOI: 10.3987/COM-08-S(F)109
Preparation and Synthetic Applications of N-(α,β-Unsaturated Acyl)-α-amino Acid Derivatives

Alan R. Katritzky,* Reena Gyanda, Nabin K. Meher, and Yuming Song

*Center for Heterocyclic Compounds, Department of Chemistry, University of Florida, Gainesville, FL 32611-7200, U.S.A.

Abstract

N-(α,β-Unsaturated acyl)-α-amino acids, amides and esters are structural motifs of many biologically active natural products. An alternate and advantageous approach for the synthesis of N-(α,β-unsaturated acyl)-α-amino acid derivatives is developed via acylation of unprotected α-amino acids with stable crystalline N-(α,β-unsaturated acyl)benzotriazole. The proposed methodology provides a new synthesis for compound (9) which is a precursor to a novel cytotoxic agent.

Full Text HTMLPDF (302KB)PDF with Links (891KB)
Paper | Special issue | Vol 77, No. 2, 2009, pp. 1261 - 1268
Published online: 18th November, 2008
DOI: 10.3987/COM-08-S(F)112
Effect of Fused Benzene Ring on Rotational Barriers of 2,2’-Bifuran, 2-Phenylfuran, Biphenyl, and Their Benzo Analogues

Naoto Hayashi,* Yoko Saito, and Hiroyuki Higuchi*

*Department of Chemistry, Faculty of Science, Toyama University, Gofuku 3190, Toyama 930, Japan

Abstract

Molecular orbital (MO) calculations of torsional potentials of 2,2’-bifuran (F-F), 2-(2-furyl)benzofuran (F-BF), 2-phenylfuran (Ph-F), 2-(2-naphthyl)furan (Naph-F), 2-phenylbenzofuran (Ph-BF), biphenyl (Ph-Ph), 2-phenylnaphthalene (Ph-Naph), 2-phenylbenzo[1,2-b:4,5-b’]difuran (Ph-BDF), and 2-phenylbenzo[1,2-b:5,4-b’]difuran (Ph-BDF’) by using HF/6-31G** and B3LYP/6-31G** methods have revealed that the rotational barriers are increased by 0.4-0.9 kcal/mol by replacement of the aryl moiety on the furan ring (furyl group of F-F and phenyl of Ph-F) with its benzo analogue. In contrast, increase of the rotational barriers is slight when the aryl moiety on the benzene ring (phenyl groups of Ph-F and Ph-Ph) is replaced with its benzo analogue and more extended π moiety.

Full Text HTMLPDF (277KB)PDF with Links (833KB)
Paper | Special issue | Vol 77, No. 2, 2009, pp. 1269 - 1283
Published online: 11th November, 2008
DOI: 10.3987/COM-08-S(F)113
Rhodium-Catalyzed Conjugate Addition of Sb-Aryl-1,5-azastibocines to α,β-Unsaturated Carbonyl Compounds

Naoki Kakusawa, Shuji Yasuike, and Jyoji Kurita*

*Faculty of Pharmaceutical Sciences, Hokuriku University, 3-Ho, Kanagawa machi, Kanazawa 920-1181, Japan

Abstract

Rhodium-catalyzed conjugate addition of Sb-aryl-1,5-azastibocines to α,β-unsaturated carbonyl compounds is describedThe rhodium-catalyzed reaction was carried out in aqueous N-methy-2-pyrrolidinone (NMP) to give 1,4-conjugate adduct exclusively, while the palladium catalyzed reaction gave only Heck-type adduct. The 1,4-addition of various aryl groups such as substituted benzenes and thiophenes was achieved with various enones and enoate.

Full Text HTMLPDF (364KB)PDF with Links (1.1MB)
Paper | Special issue | Vol 77, No. 2, 2009, pp. 1285 - 1296
Published online: 6th October, 2008
DOI: 10.3987/COM-08-S(F)114
Synthesis of Isochromanes and Isothiochromanes Bearing Fluorinated One-Carbon Units via Intramolecular Cyclizations of ortho-Substituted α-(Trifluoromethyl)styrenes

Junji Ichikawa,* Masahiro Ikeda, and Masahiro Hattori

*Department of Chemistry, Graduate School of Pure and Applied Sciences, University of Tsukuba, 1-1-1 Ten-nodai, Tsukuba-shi, Ibaraki 305-0006, Japan

Abstract

α-(Trifluoromethyl)styrenes bearing a nucleophilic oxygen or sulfur atom tethered by a methylene or methyne unit at the ortho carbon were prepared by the coupling reaction of 2-bromo-3,3,3-trifluoropropene with aryl iodides via (3,3,3-trifluoroprop-1-en-2-yl)boronic acid. The styrenes thus obtained readily undergo an intramolecular nucleophilic addition or substitution (SN2’-type) of the oxygen and sulfur under basic conditions, leading to 4-trifluoromethyl- or 4-difluoromethylene-substituted isochromanes and isothiochromanes, respectively.

Full Text HTMLPDF (453KB)PDF with Links (932KB)
Paper | Special issue | Vol 77, No. 2, 2009, pp. 1297 - 1305
Published online: 16th October, 2008
DOI: 10.3987/COM-08-S(F)115
Stereoselective β-D-Psicofuranosylation and Synthesis of β-D-Psicofuranosylceramide

Jun'ichi Uenishi* and Atsushi Ueda

*Kyoto Pharmaceutical University, Misasagi, Yamashina-ku, Kyoto 607-8412, Japan

Abstract

Psicofuranosylations of alcohols and phenol 3a-e with benzyl D-psicosyl phthalate 2 occurred on the β-face to give β-D-psicoside 4a-e in excellent yields. The reaction of ceramide 5 with 2 and deprotections of acetonide and three benzoates of the resulting glycoside afforded β-D-psicosylceramide 1.

Full Text HTMLPDF (709KB)PDF with Links (999KB)
Paper | Special issue | Vol 77, No. 2, 2009, pp. 1307 - 1321
Published online: 28th October, 2008
DOI: 10.3987/COM-08-S(F)116
New [11C]Phosgene Based Synthesis of [11C]Pyrimidines for Positron Emission Tomography

Koh-ichi Seki,* Ken-ichi Nishijima, Kimihito Sanoki, Yuji Kuge, Masayuki Takahashi, Hiromichi Akizawa, Nagara Tamaki, Leonard I. Wiebe, and Kazue Ohkura*

*Central Institute of Radio Isotope Science, Hokkaido University, Kita 15 Nishi 7, Kita-ku, Sapporo, Hokkaido 060-0815, Japan

Abstract

Thymine, 5-FU, and uracil were successfully synthesized through a procedure involving a cyclocondensation of triphosgene with newly developed α-substituted β-aminoacrylamides intermediates (1a, X = Me; 1b, X = F; 1c, X = H). The radioligands [2-11C]thymine and [2-11C]5-fluorouracil were synthesized in high radiochemical yields in 16-17 minutes from the end of bombardment by applying the cyclocondensation method with [11C]COCl2.

Full Text HTMLPDF (328KB)PDF with Links (745KB)
Paper | Special issue | Vol 77, No. 2, 2009, pp. 1323 - 1331
Published online: 23rd October, 2008
DOI: 10.3987/COM-08-S(F)119
Reactivity and Efficient Recycling of a Chiral Pd-BINAP Catalyst for Catalytic Asymmetric Diels-Alder Reaction in Ionic Liquid

Yasuhiro Nishiuchi, Hiroto Nakano,* Yuta Araki, Rina Sato, Reiko Fujita, Koji Uwai, and Mitsuhiro Takeshita*

*Tohoku Pharmaceutical University, 4-4-1 Komatsushima, Aoba-ku, Sendai 981-8558, Japan

Abstract

Chiral cationic palladium-BINAP catalyst in ionic liquid showed an excellent asymmetric catalytic activity in the Diels-Alder reactions using several dienes and the catalyst was easily recycled 7 times with good chemical yield and excellent enantioselectivity (50-60%, 94-98% ee).

Full Text HTMLPDF (795KB)PDF with Links (831KB)
Note | Special issue | Vol 77, No. 2, 2009, pp. 1333 - 1340
Published online: 22nd September, 2008
DOI: 10.3987/COM-08-S(F)45
Tandem Metathesis Reactions Cascade Ring-Opening Metathesis (ROM)-Ring-Closing Metathesis (RCM)-Cross Metathesis Dimerization (CMD) in 7-Oxabicyclo[2.2.1]hept-5-one (7-Oxanorbornene) Derivatives

Ana Aljarilla and Joaquín Plumet*

*Department of Organic Chemistry, Faculty of Chemistry, University of Complutense, 28040-Madrid, Spain

Abstract

The domino metathesis sequence ROM-RCM-CMD achieved on conveniently substituted 7-oxabicyclo[2.2.1]hept-5-ene (7-oxanorbornene) derivatives is reported. Experimental conditions in order to carry out this tandem metathetical sequence in a chemoselective fashion is also established.

Full Text HTMLPDF (227KB)PDF with Links (894KB)
Note | Special issue | Vol 77, No. 2, 2009, pp. 1341 - 1345
Published online: 18th September, 2008
DOI: 10.3987/COM-08-S(F)50
Quinoline Derivatives by Cyclocondensation of N-(2-Bromophenylmethylphenyl)benzenesulfonamide with Enol Ethers and Enamines

Giuseppe Cremonesi, Piero Dalla Croce,* Francesco Fontana, and Concetta La Rosa

*Department of Organic and Industrial Chemistry, C.N.R. - I.S.T.M., University of Milano, Via Venezian 21, I-20133 Milano, Italy

Abstract

The reaction of N-(2-bromophenylmethylphenyl)benzenesulfonamide (1) with electron rich alkenes (enol ethers (2), (3) and enamines (4)) gives quinoline derivatives 5 and ring fused quinoline 6, 7 whose structures were assigned on the basis of analytical and spectroscopic data. The chemical behavior of adducts 5 and 7 is reported.

Full Text HTMLPDF (158KB)PDF with Links (806KB)
69 data found. 31 - 60 listedFirst Previous Next Last